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authorAlexey Klimov <klimov.linux@gmail.com>2008-11-19 00:36:29 -0300
committerMauro Carvalho Chehab <mchehab@redhat.com>2008-12-30 09:38:05 -0200
commit3480130a502a528373f98fb852d2b3fc5f73e58b (patch)
tree331f7e5d900aec5a184b73bf858318f5fc54ae7b /drivers
parentc7abfb47c9e19d63ce6f757afcb392c69ce09765 (diff)
V4L/DVB (9655): radio-mr800: fix unplug
This patch fixes problems(kernel oopses) with unplug of device while it's working. Patch adds disconnect_lock mutex, changes usb_amradio_close and usb_amradio_disconnect functions and adds a lot of safety checks. Signed-off-by: Alexey Klimov <klimov.linux@gmail.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/media/radio/radio-mr800.c62
1 files changed, 54 insertions, 8 deletions
diff --git a/drivers/media/radio/radio-mr800.c b/drivers/media/radio/radio-mr800.c
index 61760019b03..7b7a1cfb121 100644
--- a/drivers/media/radio/radio-mr800.c
+++ b/drivers/media/radio/radio-mr800.c
@@ -141,6 +141,7 @@ struct amradio_device {
unsigned char *buffer;
struct mutex lock; /* buffer locking */
+ struct mutex disconnect_lock;
int curfreq;
int stereo;
int users;
@@ -207,6 +208,10 @@ static int amradio_stop(struct amradio_device *radio)
int retval;
int size;
+ /* safety check */
+ if (radio->removed)
+ return -EIO;
+
mutex_lock(&radio->lock);
radio->buffer[0] = 0x00;
@@ -240,6 +245,10 @@ static int amradio_setfreq(struct amradio_device *radio, int freq)
int size;
unsigned short freq_send = 0x13 + (freq >> 3) / 25;
+ /* safety check */
+ if (radio->removed)
+ return -EIO;
+
mutex_lock(&radio->lock);
radio->buffer[0] = 0x00;
@@ -293,18 +302,16 @@ static void usb_amradio_disconnect(struct usb_interface *intf)
{
struct amradio_device *radio = usb_get_intfdata(intf);
+ mutex_lock(&radio->disconnect_lock);
+ radio->removed = 1;
usb_set_intfdata(intf, NULL);
- if (radio) {
+ if (radio->users == 0) {
video_unregister_device(radio->videodev);
- radio->videodev = NULL;
- if (radio->users) {
- kfree(radio->buffer);
- kfree(radio);
- } else {
- radio->removed = 1;
- }
+ kfree(radio->buffer);
+ kfree(radio);
}
+ mutex_unlock(&radio->disconnect_lock);
}
/* vidioc_querycap - query device capabilities */
@@ -325,6 +332,10 @@ static int vidioc_g_tuner(struct file *file, void *priv,
{
struct amradio_device *radio = video_get_drvdata(video_devdata(file));
+ /* safety check */
+ if (radio->removed)
+ return -EIO;
+
if (v->index > 0)
return -EINVAL;
@@ -351,6 +362,12 @@ static int vidioc_g_tuner(struct file *file, void *priv,
static int vidioc_s_tuner(struct file *file, void *priv,
struct v4l2_tuner *v)
{
+ struct amradio_device *radio = video_get_drvdata(video_devdata(file));
+
+ /* safety check */
+ if (radio->removed)
+ return -EIO;
+
if (v->index > 0)
return -EINVAL;
return 0;
@@ -362,6 +379,10 @@ static int vidioc_s_frequency(struct file *file, void *priv,
{
struct amradio_device *radio = video_get_drvdata(video_devdata(file));
+ /* safety check */
+ if (radio->removed)
+ return -EIO;
+
radio->curfreq = f->frequency;
if (amradio_setfreq(radio, radio->curfreq) < 0)
amradio_dev_warn(&radio->videodev->dev,
@@ -375,6 +396,10 @@ static int vidioc_g_frequency(struct file *file, void *priv,
{
struct amradio_device *radio = video_get_drvdata(video_devdata(file));
+ /* safety check */
+ if (radio->removed)
+ return -EIO;
+
f->type = V4L2_TUNER_RADIO;
f->frequency = radio->curfreq;
return 0;
@@ -401,6 +426,10 @@ static int vidioc_g_ctrl(struct file *file, void *priv,
{
struct amradio_device *radio = video_get_drvdata(video_devdata(file));
+ /* safety check */
+ if (radio->removed)
+ return -EIO;
+
switch (ctrl->id) {
case V4L2_CID_AUDIO_MUTE:
ctrl->value = radio->muted;
@@ -415,6 +444,10 @@ static int vidioc_s_ctrl(struct file *file, void *priv,
{
struct amradio_device *radio = video_get_drvdata(video_devdata(file));
+ /* safety check */
+ if (radio->removed)
+ return -EIO;
+
switch (ctrl->id) {
case V4L2_CID_AUDIO_MUTE:
if (ctrl->value) {
@@ -500,14 +533,26 @@ static int usb_amradio_open(struct inode *inode, struct file *file)
static int usb_amradio_close(struct inode *inode, struct file *file)
{
struct amradio_device *radio = video_get_drvdata(video_devdata(file));
+ int retval;
if (!radio)
return -ENODEV;
+
+ mutex_lock(&radio->disconnect_lock);
radio->users = 0;
if (radio->removed) {
+ video_unregister_device(radio->videodev);
kfree(radio->buffer);
kfree(radio);
+
+ } else {
+ retval = amradio_stop(radio);
+ if (retval < 0)
+ amradio_dev_warn(&radio->videodev->dev,
+ "amradio_stop failed\n");
}
+
+ mutex_unlock(&radio->disconnect_lock);
return 0;
}
@@ -607,6 +652,7 @@ static int usb_amradio_probe(struct usb_interface *intf,
radio->usbdev = interface_to_usbdev(intf);
radio->curfreq = 95.16 * FREQ_MUL;
+ mutex_init(&radio->disconnect_lock);
mutex_init(&radio->lock);
video_set_drvdata(radio->videodev, radio);